Weaving is well-known. In typical loom systems, warp threads are suspended between the front and back of the loom under tension. Each thread goes through the eye of a heddle which is attached to the loom. The loom has mechanisms to raise or lower these heddles and thereby raise or lower the warp threads passing through the heddles. The opening thus created between the raised and lowered warp threads is the shed, and it is through the shed that the weft is passed.
In ordinary weaving, a warp thread can only move in two positions, up and down, but it maintains the same lateral relationship with its neighboring warp threads.
In doup leno weaving, one thread of a pair of warp threads can be made to jump over the other and back again, creating the two leno positions. These are: (a) the first thread below and to the right of the second, and (b) the first thread below and to the left of the second. However, ordinary weaving in a doup system can be achieved easily in one position only because the crossing of the warp threads between the heddles interferes with a good shed opening.
In doup systems and many conventional leno weaving systems, such as those disclosed in U.S. Pat. Nos. 2528, 946,137, and 1,067,538, loops, heddles or members of the warp pair interfere to some degree with the movement of the warp threads, causing added friction and tension which can lead to fraying or breakage of warp threads.
Other doup and conventional leno systems, such as those disclosed in U.S. Pat. Nos. 2528, 745,240, 946,137, 1,067,538, and 2,845,094, use a "ground" or "stationary" warp and a "jumper" or "leno" warp. The two warps are under uneven tension when the shed is opened and they are consumed differently, which necessitates the use of extra tensioning devices and/or a second warp beam.
Rigid-bar heddle systems, such as that disclosed in U.S. Pat. No. 1,067,538, need a large space in which to function. The loom shafts which support the heddles cannot be set closely together, thus it is difficult to adapt these heddles for use in ordinary looms.
The purpose of this invention is to create a loom-controlled means of causing a pair of warp threads to twist, that is, to cross over each other, to maintain this position while the weft is thrown, to revert to the original position for another throw of weft, and to do all this without physicial obstruction by one warp thread upon the other of by any portion of the loom or heddles upon either warp thread.
The purpose of this invention is also to create a loom-controlled means of ordinary weaving, where the weft may be placed either under or over a particular warp thread, with the warp threads in either crossed or uncrossed positions, and which can be used at any time in place of cross-weaving.
This heddle system is simple in design and in construction, and can be adapted for use on looms heretofore used only for ordinary weaving, in place of regular small-eyed or long-eyed heddles. No other special equipment is necessary.